Rotation control device for working machine

Abstract

In a rotation control device for rotating a rotation motor at speed in accordance with a boom raising operation amount, at the time of a combined operation for simultaneously performing a rotation action and a boom raising action, a limitation value of rotation torque in accordance with the boom raising operation amount is determined by rotation torque limitation value setting means of a controller, the limitation value serving as a rotation torque limitation value is sent to rotation speed control means, and a command value of the rotation torque is torque-limited by rotation torque limiting means.

We claim: 
     
       1. A rotation control device for a working machine, comprising:
 a rotation body; 
 an electric motor for rotating and driving said rotation body; 
 a hydraulic actuator driven by pressure oil from a hydraulic pump; 
 rotation operation means for sending a rotation signal to said electric motor; 
 hydraulic actuator operation means for sending an action signal to said hydraulic actuator; 
 rotation operation amount detecting means for detecting a rotation operation amount which is an operation amount of said rotation operation means; 
 hydraulic actuator operation amount detecting means for detecting a hydraulic actuator operation amount which is an operation amount of said hydraulic actuator operation means; and 
 a controller which controls said electric motor on the basis of the signals from both said operation amount detecting means, the controller including: 
 speed control means for controlling said electric motor speed in accordance with the rotation operation amount at the time of an only rotation operation, and 
 torque control means for torque controlling said electric motor, so that a driving time of the electric motor until a rotating speed increases to a target value of the rotating speed defined by the rotation operation amount is increased in accordance with an increase in the hydraulic actuator operation amount at the time of a combined operation for simultaneously performing a rotation-acceleration action and a hydraulic action by said hydraulic actuator, and so that the driving time of the electric motor at the time of the combined operation becomes longer than that of the electric motor at the time of the only rotation operation. 
 
     
     
       2. The rotation control device for a working machine according to  claim 1 , wherein
 said torque control means torque-controls said electric motor in the direction of reducing rotation torque in accordance with the increase in the hydraulic actuator operation amount at the time of the combined operation. 
 
     
     
       3. The rotation control device for a working machine according to  claim 1 , wherein
 said torque control means torque-controls said electric motor in the direction of reducing the rotation acceleration in accordance with the hydraulic actuator operation amount at the time of the combined operation. 
 
     
     
       4. The rotation control device for a working machine according to  claim 1 , wherein
 a boom cylinder for raising and lowering a boom is provided as said hydraulic actuator, boom raising operation means for sending a command for raising the boom is provided as said hydraulic actuator operation means, boom raising operation amount detecting means for detecting an operation amount of said boom raising operation means is provided as said hydraulic actuator operation amount detecting means, and said torque control means torque-controls said electric motor in the direction of slowing down the acceleration of the rotation in accordance with an increase in the boom raising operation amount. 
 
     
     
       5. A rotation control device for a working machine, comprising:
 a rotation body; 
 an electric motor for rotating and driving said rotation body; 
 a hydraulic actuator driven by pressure oil from a hydraulic pump; 
 rotation operation means for sending a rotation signal to said electric motor; 
 hydraulic actuator operation means for sending an action signal to said hydraulic actuator; 
 rotation operation amount detecting means for detecting a rotation operation amount which is an operation amount of said rotation operation means; 
 hydraulic actuator operation amount detecting means for detecting a hydraulic actuator operation amount which is an operation amount of said hydraulic actuator operation means; and 
 a controller which controls said electric motor on the basis of the signals from both said operation amount detecting means, the controller being arranged and configured for: 
 controlling said electric motor speed in accordance with the rotation operation amount at the time of an only rotation operation, and 
 torque controlling said electric motor, so that a driving time of the electric motor until a rotating speed increases to a target value of the rotating speed defined by the rotation operation amount is increased in accordance with an increase in the hydraulic actuator operation amount at the time of a combined operation for simultaneously performing a rotation-acceleration action and a hydraulic action by said hydraulic actuator, and so that the driving time of the electric motor at the time of the combined operation becomes longer than that of the electric motor at the time of the only rotation operation. 
 
     
     
       6. The rotation control device for a working machine according to  claim 5 , wherein
 said controller is arranged and configured for torque-controlling said electric motor in the direction of reducing rotation torque in accordance with the increase in the hydraulic actuator operation amount at the time of the combined operation. 
 
     
     
       7. The rotation control device for a working machine according to  claim 5 , wherein
 said controller is arranged and configured for torque-controlling said electric motor in the direction of reducing the rotation acceleration in accordance with the hydraulic actuator operation amount at the time of the combined operation. 
 
     
     
       8. The rotation control device for a working machine according to  claim 5 , wherein
 a boom cylinder for raising and lowering a boom is provided as said hydraulic actuator, boom raising operation means for sending a command for raising the boom is provided as said hydraulic actuator operation means, boom raising operation amount detecting means for detecting an operation amount of said boom raising operation means is provided as said hydraulic actuator operation amount detecting means, and said controller is arranged and configured for torque-controlling said electric motor in the direction of slowing down the acceleration of the rotation in accordance with an increase in the boom raising operation amount.